pines-demon's latest activity

If you start with an eigenstate of ##H##, ##H|\phi_i\rangle=E_i|\phi_i\rangle## then you can show that the state evolves as...

Let us write $$|\uparrow\rangle=\begin{pmatrix}1\\0\end{pmatrix};|\downarrow\rangle=\begin{pmatrix}0\\1\end{pmatrix}$$ then your initial...

I was wondering where the ##4\pi## went and where the 2 came from. Using ##h## instead of ##\hbar## should be forbidden by now…

Obviously Ohm's law holds in metals, but any true justification has to come from a fully quantum-many-body theory when you show that you...

Revolutionizing Quantum Mechanics: The Birth and Evolution of the Many-Worlds Interpretation Not my favorite interpretation, but then...

One bar magnet is a dipole. Two bar magnets is a quadrupole. Four bar magnets is an octopole. Etc. As you add more dipoles you get...

Is that even true (putting aside that you cannot bring a mass to ##c##)? Edit: looking at the magnetic field of a moving charge, the...

You all gotta love how PF can get hot on a simple question. We are already at three pages and still we do not know if OP is getting...

For entangled particles the state in the ##z##-axis is something like this...

Some Things I Have Learned From Detlef Dürr The Discovery of Neptune Revisited

And some unit systems don’t even have ##\epsilon_0## or ##\mu_0##.

Other observables have a clear picture. Positions relates to positions in space, momentum to momentum measurements and so on. The main...

There is one way to carry out that measurement if you know how to prepare the state. You just run the preparation backwards (Hermitian...

For the record, ##xp## with or without hats is not an observable, because it can't be represented directly by a selfadjoint operator...

Are you following a specific reference?